1. Field of Invention
The present disclosure is directed to systems for biomedical imaging and ranging, and more specifically to methods and systems associated with optical coherence tomography (OCT) imaging and low coherence interferometry (LCI).
2. Discussion of Related Art
Optical coherence tomography (OCT) is a two-dimensional imaging modality based on low coherence interferometry (LCI) principles. OCT has been used for non-invasive human eye retinal imaging for many years. Great interest has also been shown in the use of OCT to image anterior chamber as well as perform axial eye length measurements for refractive, cataract, and glaucoma surgical planning. See D. Huang, Y. Li, and S. Radhakrishnan, “Optical coherence tomography of the anterior segment of the eye,” Opthalmology Clin. N. Am. 17, 1-6 (2004).
However, imaging the entire anterior chamber of the eye remains challenging due to the limited scan depth of typical OCT techniques. The depth of the anterior chamber is very long compare to that of the retina. Average depth from cornea to crystalline lens is about 3.5 mm. Typically, anterior segment OCT scan depth should be about 5-6 mm. If the posterior capsule of the crystalline needs to be imaged, the depth of the image should be at least 9 to 10 mm. If the entire eye length is to be measured, the scan depth should be more than 30 mm. In performing axial eye length measurements, only two low coherence interferometry (LCI) measurements acquired from the front and back surfaces of the eye are typically utilized. However, the eye is likely to move in the axial direction between the two measurements at the two surfaces, thereby decreasing the accuracy of the eye length measurements.
Therefore, a need exists for a method that can simultaneously acquire multiple OCT images spanning multiple axial ranges in order to perform imaging and/or measurements over large scan ranges.